Improve run time of the unit tests: Half the time is spent on one test..

Description

Looking at a "normal" build done on the buildserver (ibm-redhat1) , certain tests take a large amount of time; a normal run of common-unit-test (with the current settings) takes about 22 minutes to complete:

Half of this time (630s) is spent in TestAllLocales. The next longest are TestsPaths (65s), TestPathsNotInEnglish (roughly 61s), TestAbstractPaths (55s) and TestDtdComparisonsAll (49s)